Introduction to SNAplus2
SNAplus2 Resources
| The local node can have an explicit link station defined for its |
| communication path to another node on the SATF, but enabling |
| communications between every pair of nodes on the SATF requires a |
| large number of link station definitions, and results in a large volume of |
| network topology information flowing on the network. |
| APPN enables you to set up this type of configuration without having to |
| define each link station explicitly, by defining a connection network (CN) |
| that represents the SATF. For each node on the SATF, you define one or |
| more ports used to access the connection network. Instead of defining a |
| link station to each remote node, you specify the name of a virtual |
| routing node (VRN) as part of the port definition. |
| You can think of the VRN as an imaginary node that represents all the |
| other nodes on the SATF; you can give it any name you like, but all nodes |
| on the SATF must use the same VRN name (and it must not match the |
| name of any of the real nodes on the SATF). The local node can establish |
| communications with any other node that has a port associated with the |
| same CN, by accessing the VRN (which represents all the other nodes |
| attached to the SATF), instead of requiring an explicitly defined |
| communications path between each pair of nodes. |
| When two nodes on the SATF need to communicate and both have a port |
| defined with the same VRN name, APPN can dynamically establish a |
| direct connection between them; you do not need any additional |
| configuration. |
| Because the connection is direct and does not need to go through any |
| intermediate nodes, using a connection network reduces traffic on the |
| LAN and improves performance. You should use connection networks |
| wherever possible to take advantage of this. |
| You can define CNs for communications using token ring, FDDI or |
| Ethernet DLCs. |
| To use this feature, you first define a DLC and port for each node that |
| accesses the SATF, and indicate that the port should be defined on the |
| connection network. You do not need to define any link stations; |
| SNAplus2 sets up a dynamic link station to the CN (and hence to any |
| port on it) when required. |
| In the Motif administration program, CNs are not shown as a separate |
NOTE | |
| resource, but are included as part of the configuration of SATF ports. |
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Chapter 2 | 93 |